Electromagnetic Force Could Keep Satellites Together
Using magnetic forces to hold the elements of a modular spacecraft together without mechanical connection is being studied by Cornell University's College of Engineering as part of a Northrop Grumman-led team working on the US Defense Advanced Research Projects Agency's System F6 fractionated satellite programme. F6 aims to replace the traditional large monolithic satellite with several small independently launched spacecraft flying in close formation.
Cornell is working with flux-pinning superconductors that resist movement within magnetic fields and which could be used to hold spacecraft components in place without mechanical connections. The superconductors can be turned on and off, allowing flux-pinned modules to repositioned or replaced like the "virtual building blocks" of a fractionated satellite, says the university. Cornell is also studying electromagnetic formation flight, which can passively stabilise formations of spacecraft flying in close proximity (less than 1m), while also preventing them from colliding. DARPA plans to fly a fractionated satellite within four years.
Carbon Nanotubes Could Replace Copper Wires
New Hampshire based-materials company Nanocomp Technologies is to develop electrically conductive wires, cables and materials made from Carbon NanoTubes (CNT) under a US Air Force phase one Small Business Innovation Research (SBIR) contract. Nanocomp Technologies will develop its processing methods for CNT sheets to produce wires with a conductivity performance that could replace copper wiring in aircraft. One goal of the SBIR contract is to increase the output of the CNT manufacturing process.
In February the company announced that it was able to produce CNT sheets 900 x 1830mm (36 x 72in), declaring them the "largest in the world". Nanocomp Technologies chief executive Peter Antoinette says: "It is generally overlooked that modern satellites and aircraft rely upon an invention from the 1800s, copper-based electrical wires and cables. Our work can result in...electrically optimised carbon nanotube wires and cables, comparable to copper in terms of electrical conductivity." Nanocomp Technologies claims that satellites with a mass of 13,600kg (29,900lb) or more can derive one-third of their weight from copper wiring harnesses and that commercial aircraft, such as the Boeing 747, can use as much as 217km (135miles) of the wire that is more than 1,800kg in mass. The CNT wires, Nanocomp Technologies says, could be 80% lighter than copper wiring.
Mass Production Research for Storage Vessels
Manufacturing technologies for hydrogen storage vessels are the focus of a three-year, $5.6 million US Department of Energy research contract due to begin this year. Its objective is to develop and demonstrate a manufacturing process that integrates features of high-precision aerospace and high-speed commercial manufacturing techniques.
Boeing Phantom Works and Quantum Fuel Systems Technologies Worldwide have submitted a proposal to the DoE, based on the use of composites technology for the storage vessels. As the prime contractor, Quantum would provide overall co-ordination and its hydrogen systems expertise, while Phantom Works will adapt precision composite manufacturing technologies that it has developed for the aerospace industry. Quantum chief executive Alan Niedzwiecki says: "This programme will take hydrogen storage technology one step closer to mass-commercialisation."
Solid Fuel Missile Defence Test "Success": Aerojet
California-based Aerojet has announced a successful first test firing of a miniature solid propellant divert and attitude control system (DACS) being developed for the US Missile Defense Agency. The test follows "several years" of Aerojet's internal research and development of solid propellant technology for DACS under its contract with the US Army Space and Missile Defense Command and Army Forces Strategic Command. DACS would be used for divert and attitude control of missile defence interceptors.
Aerojet defence programmes vice-president Dick Bregard says: "This system leverages the mature throttling solid DACS technology currently under development for the SM-3 Block 1B Interceptor programme and other potential applications." Aerojet claims the solid propellant technology's safety and "insensitive munitions characteristics" make it attractive for mobile and sea-based interceptor deployments.
BAE, USAF to Develop Situational Awareness Tools
BAE Systems and the US Air Force are to jointly develop new software and information management tools to improve the situational awareness of air commanders. Under a 30-month co-operative research and development agreement with the USAF's Electronic Systems Center, BAE will work with the centre to identify and demonstrate technologies, capabilities, products, and processes that allow tactical decision-makers to plan, direct, co-ordinate and control forces and operations more efficiently.
"Working with the Electronic Systems Center will provide a better understanding of the Air Force's emerging needs," says BAE battle management and command, control, and communications systems division manager David Logan. BAE's virtual battle management prototyping laboratory will be networked to facilities at Hanscom Air Force Base in Lexington, Massachusetts, to support joint experimentation. The virtual lab currently consists of BAE's facilities in Burlington and Colorado Springs, Colorado, and will be helped by other by other labs owned by the company during the research.
Source: Flight International
